December 13th, 2010

False-Positive CT Angiogram Leads to Heart Transplant

A 52-year old woman with atypical chest pain ended up with a heart transplant after a CT angiogram to “reassure” her sparked a devastating sequence of events. Following a false-positive CT angiogram, the patient underwent coronary angiography and suffered a dissection of the left main coronary artery, followed by emergency CABG, subsequent graft failure, and multiple additional complications. The case report from the Cleveland Clinic is published online in the Archives of Internal Medicine.

“We believe that in this case the unwarranted use of advanced diagnostic imaging (false-positive CCTA findings) directly contributed to unnecessary cardiac catheterization that resulted in a tragic complication and significant morbidity,” write the authors. “In an era in which comparative efficacy of therapies has assumed critical importance, the unchecked growth of CCTA seems not only unfounded but also irresponsible and unsustainable.”

In an accompanying editorial, Archives editor Rita Redberg and colleagues write that the case is another illustration that “less is more … if a test is not sufficiently accurate to change clinical management in a particular setting, it should not be done.”

6 Responses to “False-Positive CT Angiogram Leads to Heart Transplant”

  1. Stephen Austin, MD says:

    Amen!! Also contributes to spiraling, unchecked costs of health care in the U.S.

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  2. A clear example of inappropriately applied technology. The technology to criticize is the catheter angiogram, not the CTA.

    How much obstruction did the “false positive” CTA demonstrate? Was there any reason to think that an invasive angiogram would improve the individuals prognosis? If there was plaque, that should have led to a statin, not to an angiogram.

    It is amazing that new technology is criticized for the failures of old technology. This demonstrated that angiography should be avoided whenever possible and the CTA is the best test around to avoid unnecessary angiographies in subjects with atypical chest pain.

    The fact that Dr Redberg would use this bizarre case as proof of concept that CTAs are not accurate enough to use in the fact of the mountain of DATA otherwise is patently absurd!

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    I do not perform or order coronary CTAs and feel that they should not be used as screening tests. Coronary calcium imaging is the screening test of choice as it has a very high sensitivity and a specificity of nearly 100%. In addition, coronary calcium imaging directs therapy with great regularity. I assume that Dr. Redberg orders CAC regularly as it should fulfill her above criteria.

  3. You are right Dr.Blanchet. I think there are many patients who suffered due to unnecessary CTA all over the world. For detecting coronary artery disease, the best solution must be the screening of coronary artery calcification.

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  4. It seems to me that the authors have conflated likelihood of obstructive CAD with FRS-derived risk of CHD events.

    While they are correct in stating that the risk of CHD over 10 yrs is <10% (low risk), a 52 year-old obese female with h/o HTN and ATYPICAL CHEST PAIN has an INTERMEDIATE likelihood of having obstructive CAD. A CT angiogram would be quite reasonable in this patient provided CAC score <400. No mention is made of CAC score but LAD had a complex calcified lesion that precluded evaluation of luminal stenosis. Even if the CT angiogram was accurate in diagnosing LAD stenosis, how would one have prevented a rare, but known, complication of invasive angiography? I think the authors' and the editorialists' comments are on target but for the wrong reason.

    I think CT angiogram is quite reasonable for someone with intermediate likelihood of CAD. The PPV of 90% and NPV of 98% of the test means that a positive test would increase the pretest probability from 30% to about 80% and a negative test would reduce the probability to under 2%. I would regard such a test to have clinically important diagnostic yield.

  5. I’m sure similar unfortunate bad outcomes have occurred following “unneccesary caths” following false positive ETTs, MPIs, stress echos, etc. Coronary CTA is not the only noninvasive modality that may yield false positives. This case illustrates a complication of an invasive angiogram, a false positive CTA is not a complication.

    Regarding the issue of CTAs reducing the number of “unneccesary caths”, an analysis from our institution found no effect from implimentation of CTAs on the diagnostic yield of invasive coronary angiograms.

  6. Mark Berry, D.O., M.S. says:

    I have seen cases in which patients were taken to the cath lab with out imaging or stess tests and they also had bad outcomes. If the CTAs are used appropriately, they can be beneficial. Any test can be used inapproiately. I do not believe it is just CTA that is the problem.

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